CMAKE_CXX_EXTENSIONS
--------------------

.. versionadded:: 3.1

Default value for :prop_tgt:`CXX_EXTENSIONS` property of targets.

This variable is used to initialize the :prop_tgt:`CXX_EXTENSIONS`
property on all targets.  See that target property for additional
information.

See the :manual:`cmake-compile-features(7)` manual for information on
compile features and a list of supported compilers.